Tool alloy



Patented Nov. 3, 1942 UNITED STATES PATENT OFFICE TOOL ALLOY Charles J. Schafer, Baltimore, Md.

NoDrawing. Original ap Serial No. 393,262. Di tion February 2, 1942,

4 Claims.

This application is a division of my copendingapplication, Serial No. 393,262, filed May 13, 1941.

My novel alloys may be used to great advantage in place of many of the alloy and carbon steels, but without the necessity of tempering the products except in very special cases involving the more intricately formed tools such as certain twist drills, threading dies and some similar tools, which have to be forged or drawn into shape and then completed by hardening. The novel alloys are subject to some variation in their iron content depending upon the desired resistance to the action of acids or to tarnishing, for example due to the sterilizing medium which may be used. The alloys are generally non-corrosive and nontarnishing and resistant to many acids,

and they may be welded, forged, swaged, heated,

and reheated with a minimum of loss.

The chief constituents of the new alloys are zirconium, tungsten, and columbium, the last named being combined with a certain amount of tantalum which occurs in the same ores and which it is 'noi; necessary to eliminate, since it lends certain desirable qualities to the alloy. I have found that the novel alloy is superior in properties, including its hardness and tensile strength to the tungsten, molybdenum, vanadium, nickel, and chrome steels which are now in widespread use.

The alloys may be produced in bar stock or cast in the ultimate form of tool or other product in which it is to be used. Unlike certain prior products they are not made from sintered or granular materials compacted under pressure, such as for example tungsten-carbide, and the alloy may comprise the entire tool instead of made as a tip for a steel shank as in the case of certain other cutting products.

The general range of percentages of the variplication May 13, 1941,

vided and this applica- Serial No. 429,339

bus elements comprising the group of alloys pro- I'vided by the present invention may be set forth as follows:

Per cent Zirconium From 10 to 40 Columbium From 3 to 20 Tantalum From 1 to 8 Titanium From none to 15 Tungsten In appreciable amounts up to o 25 Iron Balance Conveniently, the columbium and the tantalum are introduced in combination since they are obtained from the same ores in the pre-melt or reduction step, as will be more clearly understood as the specification proceeds.

For a cutting tool for general use or for the preparation of a bar stock for the making of tools, the following two formulas may be employed. The first will yield a stock having a hardness of 75 on the Rockwell-C scale, and the second will have a hardness of on the same scale.

Hardness v v Per cent Zirconium About 30 Columbium About 12 Tantalum About 2.5 Titanium About 7.5 Iron About 48 Hardness 65 Per cent Zirconium About 35 Columbium About 14 Tantalum About 3 Iron About 48 bium and tantalum reduced by about one-half,

and the balance subtracted from the iron content. This willyield an alloy of the following approximate composition: I

- Per cent Zirconium '30 Columbium 6 Tantalum 1.5 Titanium 3 Tungsten 15-25 Iron Balance Another suggested formula, within the scope of the invention, and particularly adapted for the manufacture of high grade drawing and cutting dies, is as follows, the percentages of ingredients being approximate:

, Per cent Zirconium 30 Columbium 15 Tantalum 4 Timgsten 8 Iron 43 In producing these alloys, certain of the constituents are preferably reduced'directly from their ores, and reference is made to my copending application, Serial No. 393,262, and to my application, Serial No. 412,500, which is a continuation-in-part of the first named application,

for a complete disclosure of the preferred modes of producing the novel alloys which comprise the subject of the present application.

' comprises 10% .lum, from appreciable Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

1. A hard, high-tensile strength alloy suitable for high speed cutting tools or the like, which to 40% zirconium, 3% .to columbium, 1% to 8% tantalum, from appreciable amounts up to 15% titanium, from appreciable amounts up to tungsten, and the balance iron. v

2, A hard, high-tensile strength alloy suitable for high speed cutting tools or the like, which comprises -10% to 40% zirconium, 3% to 20% columbium, 1% to 8% tantalum, 3% to 15% titanium, 15% to 25% tungsten, and the balance iron.

3. An alloy suitable for drawing and cutting dies which comprises about zirconium, from 15% to 8% columbium, from 4% to 2% tantaamounts up to 5% titanium, from appreciable amounts up to 8% tungsten, and the balance iron.

4. A hard, high-tensile strength alloy suitable for high speed cutting tools or the like, which comprises from 10% to 40% zirconium, from 4% to 28% columbium and tantalum combined, from appreciable amounts up to 15% titanium, from appreciable amounts up to 25% and the balance iron.

CHARLES J. SCI-IAFER.

tungsten, 

